1. Field of Invention
The present invention relates generally to the field of sputtering targets, and more particularly, to a method of making sputtering targets using circular groove pressing.
2. Description of Related Art
Sputtering targets require certain metallographic attributes in order to achieve acceptable sputtering uniformity. Typically, metal targets are made by a combination manufacturers have relied upon several processing techniques to manufacture sputter targets from aluminum alloys such as, aluminum-copper, aluminum-silicon and aluminum-silicon-copper alloys. Manufacturers have traditionally relied upon a combination of thermo-mechanical processing including forging, pressing, annealing and rolling to produce a fine-grained aluminum alloy target. The annealing recrystallizes the grains to produce a useful grain texture for sputtering. The final grain size of these annealed targets typically ranges from 30 to 75 μm.
Most of the targets used for semiconductor manufacturing are in disc shape and have cylindrical symmetry. However, typical thermo-mechanical treatments are predominantly based on uniaxial pressing, forging and one directional rolling. To prevent formation of a directional texture, cross rolling is sometimes used.